DHA DOCOSAHEXAENOIC ACID Overview Information

Don’t confuse DHA with EPA (eicosapentaenoic acid). They are both in fish oil, but they are not the same. DHA can be converted into EPA in the body. See separate listings for fish oil and EPA.

DHA is used as a supplement for premature babies and as an ingredient in baby formula during the first four months of life to promote better mental development. This practice probably started because DHA is found naturally in breast milk. DHA is also used in combination with arachidonic acid during the first four to six months of life for this purpose.

It is also used in combination with evening primrose oil, thyme oil, and vitamin E (Efalex) to improve movement disorders in children with a condition called dyspraxia.

How does it work?

DHA plays a key role in the development of eye and nerve tissues. DHA may also reduce the risk of heart and circulatory disease by decreasing the thickness of the blood and lowering blood levels of triglycerides.

DHA DOCOSAHEXAENOIC ACID Uses & Effectiveness

Age-related macular degeneration (AMD). Increased consumption of DHA in the diet is associated with a lower risk of developing vision loss due to aging.

Clogged arteries (coronary artery disease). Increased consumption of DHA in the diet might lower the risk of death in people with coronary artery disease.

High cholesterol. Research suggests that taking 1.2-4 grams of DHA daily can lower triglyceride levels in people with high cholesterol. DHA does not seem to lower total cholesterol, and might increase both high-density lipoprotein (HDL or “good”) cholesterol and low-density lipoprotein (LDL or “bad”) cholesterol.

Attention deficit-hyperactivity disorder (ADHD). Many children with ADHD have low levels of DHA in their blood. However, taking DHA does not seem to improve ADHD symptoms, although some early research suggests that DHA might help children with ADHD become less aggressive and get along better with others.

Mental performance. Research suggests that taking 400-1000 mg of DHA daily for 2-4 months does not improve mental performance in healthy children. Taking DHA daily for 4 months also does not improve memory and learning in elderly women.

Depression. Taking DHA by mouth does not seem to relieve depression symptoms.

Diabetes. Taking DHA by mouth does not seem to lower blood sugar or cholesterol in people with type 2 diabetes.

Alzheimer’s disease. Some research suggests that getting more DHA from the diet might help to prevent Alzheimer’s disease. However, evidence suggests that taking 2 grams of DHA daily for 18 months does not slow mental or functional decline in people with Alzheimer’s disease.

Cystic fibrosis. Early research suggests that taking 70 mg per kg of body weight of DHA for 6 weeks might not improve lung function in people with cystic fibrosis.

Dementia. Early research suggests that taking 0.72 grams of DHA daily for one year might improve symptoms of dementia.

Dyslexia. Taking DHA by mouth seems to improve night vision in children with dyslexia.

Movement and coordination disorder (dyspraxia). Taking DHA by mouth together with evening primrose oil, thyme oil, and vitamin E (Efalex) seems to improve movement disorders in children with dyspraxia.

Improving infant development. Evidence about the effects of DHA on infant development is inconsistent. There is some evidence that infants who do not receive DHA from breast milk or formula have delayed mental and visual development compared to those who receive enough DHA. Some researchers reasoned that giving DHA in formula might improve development. However, when they tested this theory, study results did not agree. The reason for the differences may be due to the way the studies were designed. For now, experts generally recommend breast-feeding instead of formula-feeding. However, if formula is used, some experts suggest a formula providing at least 0.2% of fats from DHA.

Liver disease (nonalcoholic fatty liver disease). Early research suggests that taking 250-500 mg of DHA daily for 6 months reduces the risk of severe fat accumulation in the liver in children with liver disease.

Prostate cancer. Some results from clinical research suggest that higher levels of DHA in the blood are linked with an increased risk of developing prostate cancer that grows rapidly. However, other evidence shows that higher intake of DHA in the diet reduces the risk of developing this type of prostate cancer. Also, some research suggests that higher intake of DHA in the diet is linked with a reduced risk of developing prostate cancer that spreads to other tissues.

Inherited vision loss (retinitis pigmentosa). Evidence on the effectiveness of DHA for people with an inherited condition causing vision loss is inconsistent. Some research suggests that taking 1200 mg of DHA daily for 4 years does not improve eye function in people with retinitis pigmentosa who are also taking vitamin A. However, taking 400 mg of DHA daily for 4 years seems to improve eye function in some people, but visual function does not seem to improve.

Other conditions.

More evidence is needed to rate DHA for these uses.

DHA DOCOSAHEXAENOIC ACID Side Effects & Safety

DHA is LIKELY SAFE for most people when taken by mouth. DHA can cause nausea, intestinal gas, bruising, and prolonged bleeding. Fish oils containing DHA can cause fishy taste, belching, nosebleeds, and loose stools. Taking DHA with meals can often decrease these side effects.

DHA is POSSIBLY SAFE when taken by mouth in large amounts. When used in amounts greater than 3 grams per day, fish oils containing DHA can thin the blood and increase the risk for bleeding.

DHA is POSSIBLY UNSAFE when used in large amounts. When used in amounts greater than 3 grams per day, fish oils containing DHA can thin the blood and increase the risk for bleeding.

Special Precautions & Warnings:

Pregnancy and breast-feeding: DHA is LIKELY SAFE when used appropriately during pregnancy and breast-feeding. DHA is commonly used during pregnancy and is an ingredient in some prenatal vitamins. DHA is a normal component of breast milk and is added as a supplement to some infant formulas.

Aspirin-sensitivity: DHA might affect your breathing, if you are sensitive to aspirin.

Bleeding conditions: DHA alone does not seem to affect blood clotting. However, when taken with EPA as in fish oil, doses over 3 grams daily might increase the risk of bleeding.

Diabetes: DHA seems to increase blood sugar in people with type 2 diabetes.

High blood pressure: DHA can lower blood pressure and could lower blood pressure too much in people who are also taking blood pressure medications. If you have high blood pressure, check with your healthcare provider before taking DHA.

Saynor R, Gillott T. Changes in blood lipids and fibrinogen with a note on safety in a long term study on the effects of n-3 fatty acids in subjects receiving fish oil supplements and followed for seven years. Lipids 1992;27:533-8. View abstract.

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